An electronic storage system may include multiple storage clusters providing block storage services to hosts. For example, an electronic storage system may utilize a Small Computer System Interface (SCSI) Input/Output (I/O) bus to connect multiple storage blocks to one or more host systems. Each storage cluster may have a number of storage controllers acting as cluster nodes, i.e., the controllers may provide hosts with access to Logical Units (LU)/storage devices provisioned via the physical drives connected to the storage controllers. Typically, each controller in a storage cluster may then access each physical drive in the storage cluster. Further, any LU in the cluster may generally be accessible via any controller in the storage cluster.
As storage requirements for a particular installation change over time, it may often be desirable to consolidate some of the storage clusters into a larger, combined storage cluster. In this manner, the total capacity of a storage cluster may be increased. Additionally, it may be desirable to preserve data from the different storage clusters such that it may still be accessible in the new, larger storage cluster. One approach to such a consolidation is to move the controller nodes and the storage devices (physical drives) from one storage cluster (referred to as a source cluster) to another storage cluster (referred to as a destination cluster). This may be described as importing one storage cluster into another storage cluster. Typically, the resulting storage cluster may include the name/Identification (ID) of the destination cluster, while containing the storage controllers (nodes) of both the source and destination clusters, and the associated storage devices.
Typically, two storage clusters are merged by removing one controller/node at a time from a source storage cluster and then adding each node to a destination storage cluster. This process is then repeated until all of the nodes from the source storage cluster have been moved into the destination storage cluster. Further, all of the physical drives associated with the source storage cluster must be moved to the destination storage cluster. However, moving one cluster node at a time may require performing a number of individual management operations, in addition to changing cabling, moving physical drives, and the like. This process may be error prone, time consuming, and may complicate the process of moving data from the source storage cluster to the destination storage cluster. For example, the LU configuration of the source storage cluster may have to be recreated in the destination storage cluster, and the data may have to be reloaded from backup media.